7821602861 has 2 divisors, whose sum is σ = 7821602862. Its totient is φ = 7821602860.

The previous prime is 7821602843. The next prime is 7821602897. The reversal of 7821602861 is 1682061287.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7304949961 + 516652900 = 85469^2 + 22730^2 .

It is an emirp because it is prime and its reverse (1682061287) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7821602861 - 2⁶ = 7821602797 is a prime.

It is a super-2 number, since 2×7821602861² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7821602561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3910801430 + 3910801431.

It is an arithmetic number, because the mean of its divisors is an integer number (3910801431).

Almost surely, 2^7821602861 is an apocalyptic number.

It is an amenable number.

7821602861 is a deficient number, since it is larger than the sum of its proper divisors (1).

7821602861 is an equidigital number, since it uses as much as digits as its factorization.

7821602861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 7821602861 is about 88439.8262153426. The cubic root of 7821602861 is about 1985.0216766980.

The spelling of 7821602861 in words is "seven billion, eight hundred twenty-one million, six hundred two thousand, eight hundred sixty-one".